As someone who has now played two MMOs with a content finder, let me tell you that it was easier for me in those MMOs to make friends after the content finder than before. People in general wanted to play with others on their server because it meant that they would see them again. Granted I played a highly sought after role in WOW, but I would receive tells from 4-5 different people within a minute of logging in.
Content finder acts simply as a net for the people who don't have a good linkshell or friends, and who are having no luck shouting or recruiting from their local player pool.